Study on the Coking Characteristics of Coking Coal and Biomass/Biochar during Pressure-Molded Pyrolysis

Abstract— This study aims to investigate the effects of coking coal properties, forming pressure, and the proportion of various additives on the quality, coking behavior, and microstructure of formed coke. The results show that, in strongly caking coal, the compressive strength of formed coke first increases and then decreases with increasing additions of biochar and biomass. Under a forming pressure of 100 MPa, the compressive strength reaches its maximum when the addition ratios of biochar and biomass are 12 and 9%, respectively, and the caking index of the coal blends are 77.75 and 84.87. At 150 MPa, the compressive strength of biochar-based formed coke is generally higher than that of biomass-based formed coke. In weakly caking coal, the compressive strength of formed coke gradually decreases with increasing proportions of biochar and biomass; under 100 MPa forming pressure, the compressive strength of biomass-based formed coke is generally higher than that of biochar-based formed coke.